docs: def get_provides(self, ignored=tuple()):
          """ a map of provided classes and class members, and what
          provides them. ignored is an optional list of globbed patterns
          indicating packages, classes, etc that shouldn't be included
          in the provides map"""
  
          if self._provides is None:
              self._collect_requires_provides()
  
          d = self._provides
          if ignored:
              d = dict((k, v) for k, v in d.items()
                       if not fnmatches(k, *ignored))
          return d